Planning Trajectories for a Robot Manipulator with Tool Orientation in Semiautomatic Control Systems

Abstract

Today, due to digitalization, it is important to extend the functional capabilities of state-of-the-art robot control systems. In the paper, we consider digital semiautomatic control systems of robot manipulators with tool position and orientation set on a tool’s trajectory by a human operator using multi-degree-of-freedom master handles. The programs for preliminary planning of the robot links’ trajectories in offline mode were developed with the use of iterative numerical methods. Known theoretical methods of tool orientation are discussed. The problems of planning with different ways of tool orientation setting are formulated. We analyzed iterative algorithms with and without calculating the robot’s Jacobi matrix. The algorithms based on solving the nonlinear least squares problems in suggested formulations were recommended. Examples of planning link trajectories for a 6-link robot are presented when a tool moves along a square piecewise 3D trajectory. Different techniques of tool orientation setting on the trajectory pieces were applied. Testing of planned trajectories was carried out using the robot animated model. The results of the work can be implemented in computer simulators for study and design of modern digital semiautomatic control systems of robot manipulators.